Crimping tool



Jan. 25, 1966 w. s. PEARSON 3,230,756

CRIMPING TOOL Filed July 20. 1961 IN V EN TOR. h//4 4 4M ,Qa-Aeso/V United States Patent O The present invention relates to improvements in crimping tools and more particularly concerns a new and im- 4:proved device especially useful in processing electrical wires for eifecting electrical connections and in connecting such wires together.

In the course of installing electrical wiring, it is necessary, among other things, to cut the Wires to length, strip insulation from end portions thereof, and connect various end portions of such wires together. This generally requires separate tools, namely, a cutter, a stripper, and a soldering tool, or a crimping pliers where a connecting fer-rule or sleeve is employed. The amount of force required for operation of the various tools varies substantially from stripper, to cutter to attaching or crimping, at aprogressively increasing rate in the order named. In eifect, of course, all of such tools are basically crimping tools in that they crease the work as an incident to performing their functions.

According to the present invention, a single tool is provided which is equipped to perform all ofthe functions of separate stripping, cutting and crimping tools with utmost efficiency.

An object of the present invention is to provide a new and improved crimping tool which will perform various crimping functions with an unusually eicient leverage action.

Another object of the invention is to provide a novel crimping tool having an arrangement of jackknife-like levers equipped with force-multiplying means enabling quick opening and closing actions and a highly multiplied force exertion capability as the levers approach a closed or side-by-side relationship.

A further object of the invention is to provide a novel crimping tool employing a combination of gear and long lever coaction in attaining crimping leverage force.

Still another object of the invention is to provide a new and improved crimping tool which is not 'only equipped for high leverageV etliciency but is also provided with novel resilient pressure compensating or equalizing means to relieve damaging over-compression forces in use.

Yet another object of the invention is to provide new and improved crimping means for electrical wire connector ferrules or 'sleeves constructed and arranged to deform the connectors in a manner to attain unusually secure electrical and mechanical connection of the wires encompassed by the connector.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawing, in which:

FIGURE l is a side elevational View lof a crimping tool embodying features of the invention;

FIGURE 2 is an `elevational view of the tool looking to the right of FIGURE l;

FIGURE 3 lis an enlarged fragmentary detail View of the `connector crimping jaws of the tool showing the same in crimping relationship;

FIGURE 4 is an enlarged fragmentary sectional detail view taken substantially on the line IV-IV of FIGURE 1;

FIGURE 5 is an enlarged fragmentary sectional detail view taken substantially on the line V-V of FIGURE 1;

FIGURE 6 is an enlarged fragmentary sectional detail 3,230,756 Patented Jan. 25, 1966 View taken substantially on the line VI-VI of FGURE 1, and

FIGURE 7 is an enlarged sectional detail view taken on line VI1-VII of FIGURE 3.

In the illustrated embodiment of the invention, a pair of handle levers 10 and 11 is pivotally connected adjacent one end thereof by a yoke or coupling structure 12 for generally jackknife opening and closing action. One suitable form of pivotal connection comprises respective rivets 13. By disposing the pivots V13 properly spaced apart and by having the pivoted end portions or heads of the handle levers 10 and 11 properly relatively constructed, the handle levers are swingable, from parallel side-by-side contiguity at one side of the head coupling 12, about the pivots 13 to the other side of the head coupling 12 into parallel contiguity of the opposite sides of the handle levers.

In length, the handle levers 10 and 11 are such as to venable ready grasping and manipulation in one hand of the user during crimping, although two hands maybe used to swing the handle levers from 'one side-by-side orientation into the opposite side-by-side orientation. On their grasping portions, the handle levers 10 and 11 arefpreferably of a smooth rounded form such as cylindrical, and for lightweight are yof tubular construction, thus providing substantial elongated storage chambers 14 therein within which may be stored a supply of parts such as electrical connector sleeves or ferrules to be employed in effecting electrical connections between theend portions of kelectrical wires by use of the present tool. At the free ends of the handle levers lt and 11 the chambers 14 are open and are adapted to be closed by respective end closure screw caps 15 engageable with suitable thread ribs 17 provided on the handle lever free end portions as shown in respect to the handle lever 11 in FIGURE l.

It will be observed that the handle levers lil and 11 are substantially identical, complementary counterparts one of the other. While the handle levers may be constructed as one piece castings or forgings, they may conveniently be formed as sheet metal stampings, in one practical form 'having been made from l14 gauge 1020 cold rolled steel. Each of the handle levers comprises a pair of mirror image stampings which lit together to provide a hollow Vhand grip tubular portion 18 and a laminar, tiattened, double thickness elongated head portion 19 projecting on the axis of the hand grip portion 18. Although the stamped shells comprising the handle levers may be secured together by welding lor other suitable expedient, they are conveniently secured together by the rivets forming the pivots 13. At the same time, the heads 19 are maintained in coplanar relation by the coupling structure 12 so that the respective edges of the heads 19 are opposed to one another in the assembly, with the opposed longitudinal edges of the heads being related for crimping coaction.

In `order to stabilize and substantially equalize the lever action of the handle levers 10 and 11, the terminal extremities of the heads 19 are constructed as segmental gears and are thus provided with respective series of crown gear teeth Ztl in meshing relation whereby the swinging or leverage motion of each of the handle levers is coordinated to be equal though opposite or opposed.

For crimping electrical wire connector sleeves or ferrules, the handle lever heads 19 are provided with coactive crimping jaw structure. For this purpose, the confronting longitudinal edge of one of the heads 19 is 'equipped with a coplanar laterally extending crimping jaw projection 21 while the opposite confronting head edge is provided with a complementary crimping jaw recess socket 22 receptive of the crimping jaw projection 21. Through this arrangement, a connector vferrule 23 having the stripped ends of a plurality of electrical wires 24 encompassed therein is engageable in the crimping 'same time pushing the wire iirmly together in an electrical connection of which the metal ferrule becomes an in- 1 tegral part. By having the crimping jaw structure 21, 22 as near to the pivots 13 as practicable, the highest leverage eiiiciency is attained and thus the most powerful crimping force can be applied as the handle levers and 11 are forced toward one another by manual compression applied to the hand grip portions 1S.

Increased crimping effectiveness of the crimping jaw projection 21 is attained by providing the same with a crimping nose which is narrower than the body of the projection 21 and because of its relatively narrow dimension drives relatively easily into the side of the ferrule 23 during crimping. At each side ofthe projection 21 adjacent to the base of the crirnping nose 25 is a shorter terminal crimping projection 27 which alfords a final digging inland crimping, creasing .of the errule 23 as the crimping action nears completion.

Complementary to the crimping nose structure on the projection 21, the crimping jaw socket 22 has a relief recess 28 which opposes the crimping jaw nose 25 and is fianked by a pair of crimping jaw projections 29 which generally oppose the sides of the crimping jaw nose 25 and coact with the terminal crimping jaw noses 27 to effect binding creases in the wall of the ferrule 23.

In utilizing the tool for electrical wire connector crimping, the handle levers 10 and 11 are swung apart, or at least are maintained in the relatively divergent open position substantially as shown in FIG. l wherein the jaw projection 21 is sufficiently clear from the jaw recess 22, to receive in nested relation in the recess the connector ferrule 23 With the electrical wire ends 24 encompassed therein. Then the handle levers 10 and 11 are manipulated through the hand hold portions 18 thereof toward one another, whereby the jaw structure 21, 22 is closed onto the ferrule 23 in crimping relation. This crimping action of the jaw structure is substantially uniformly equalized by virtue of the segmental gear head structure wherein the meshed gear teeth 2@ compel the equalized closing movement of the handle levers during the compression, crimping coaction thereof. As a result, the jaw nose 25 drives toward the opposing jaw projections 29 and the jaw projections 29 drive substantially equally toward the jaw nose 25. However, because the jaw nose 25 is a single crimping projection as compared to the dual jaw projections 29, there is initial rapid and relatively deep cr'unping projection of the crimping nose 25 into the wall of the connector 23 and a lesser projection of the dual jaw elements 29 into the generally opposite side of the wall of the connector ferrule 23. As the crimping compression multiplies due to the short distance of the crimping jaws from the pivots 13 as compared to the length of the head portions 19 and the hand grip portions 18 of the handle levers, the coaction of the opposed gripping jaW elements 25 and 29 approaches equal crimping compression and thus exceedingly effective, thorough crushing deformation of the wall of the connector ferrule 23 onto the wires 24. This is supplemented in the last phase of crimping compression by the crimping action of the jaw projections 27 against those portions of the sleeve 23 which tend to spread laterally from the jaw elements 25 and 29 toward the side walls defining the jaw recess 22. Thus, in the .final phase of crimping compression, the jaw projections 27 drive the opposed portions of the connector ferrule 23 toward the curved edge defining the recess 22 leading toward the crimping jaw projections 29 and thus crowd the engaged lateral portions of the ferrule toward the crimping jaw elements 25 and 29, so that every portion of the sleeve within the crimping jaw is positively firmly crimped and crowded bin-dingly toward and against the encompassed wires 24, and the wires correspondingly pinched together with the greatest firmness. This final crimped relationship is visualized within the limitations of line drawing in FIG- URE 3.

Additional crimping retention of the wires 24 within the sleeve 23 is attained by having the portions of the laminations of the head 19 of each of the arms comprising the jaw elements 25 and 29 rounded 0H transversely to the planes of the laminations as shown in FIG. 7 to provide supplementary jaw points or edges 25a and 29a, \respectively. These supplementary jaw edges form corrugated ridges 23a in the ferrule 23 and corresponding serration-like interlock grooves in the relatively softer wire 24. Not only does this transverse corrugation of the ferrule act to prevent springback of the crimped ferrule wall, but affords an interlock engagement with the wires holding them against pulling out of the ferrule with great advantage. For crimping large ferrules onto large cable ends, the crimping tool may be provided with several laminations, and even with spacers between the laminations to emphasize and increase the transverse interlock crimping and rigidifying of the crimped ferrule.

It will be observed that by virtue of the complete reversibility of the handle levers 10 and 11 to Vbring the respective opposite edges of the head portions 19 into operative contiguity, it is possible with the crimping tool of the present invention to provide duplicate sets of jaws on the respective opposingly cooperative edges of the heads 19. To this end, that edge of the head 19 of the handle lever 10 which is opposite to the edge having the jaw projection 21 is provided with a directly opposite jaw socket recess 22', in all respects similar to the jaw recess 22, inclusive of a :small clearance recess extension 28 -and jaw projections 29. On that edge of the crimping heard 19 of the handle lever 11 opposite the jaw recess 22 there is provided a jaw projection 21 having a jaw nose 25 and auxiliary projections 27 and adapted to coact with the structure defining the jaws recess 22 when the handle levers 10 and 11 are swung around from the position shown in FIGURE l to bring said opposite edges of the crimping heads 19 toward one another. While the crimping jaw projection 21 and the crimpingvjaw recess 22' may be of the same size as the counterpart jaw structures 21 and 22, they may be of a different size, either smaller or larger to accommodate respectively different size electrical connector ferrules 23. It has been found, however, that within the limits of the dimensions of the clearance recess portions 28 and 28 smaller size ferrules can be readily crimped in relatively larger size crimping jaws. Therefore, if preferred, both sets of crimping jaws may be of a standard size for prolonging the life of the tool to double the length of time that would be afforded until one set of crimping jaws alone would wear out.

A second generically crimping function of the present tool is afforded by providing the heads 19 on the edges thereof adjacent to the ferrule crimping jaws,.with tapered, substantially knife edge cut-off crimper cutter blade edge portions 30, equal and coactively complementary on the respective opposing edges of the heads 19. To facil# itate cut-off, the blade edges 30 are formed on only one of the laminations of each of the heads 19, while the companion lamination has a clearance recess 30a aligned with the cutting edge in each instance asbest seen in FIG. 4. Since wire cutting does not'necessarily require as much leverage force as is desirable. for wireconnector crimping, the cut-off crimper edge portions.. are disposed along the head edges spaced lfarther away from the pivots 13 than the jaws 21, 22. Furthenxthe tapered cut-ofi crimper blade edge portions 30 are located clear of the coupling structure 12 but contiguousv thereto, so

'that a wire to be eut can be readily received within the kbifurcation defined by the handle levers and 11, and

the adjacent portion of the coupling structure 12 will serve -as a stop or abutment or locator -for the wire between the opposed, aligned, coactive cut-off crimper edge portions 30. During cut-olf, of course, the adjacent electrical connector crimping jaws are free for non-operating telescoping interrelationship. As the cut-off edge portions 30 are squeezed toward one another with a wire W therebetween, the wire is severed by the crimping, creasing, cutting coaction of the opposed knife edges. The wire W may be insulated as shown or non-insulated.

For a third crimping function of the tool, wire stripping means are provided, conveniently comprising in each of the opposing edges of the heads 19 complementary,

semi-circular stripping cutter edges 31. These stripping edges are located adjacent to but-beyond the wire cutter blade portions 36 relative to the pivots 13, since for stripping even yless leverage pressure is needed than for wire cutting. As -a matter of eiciency, the stripping edges 31 are formed'only on one of the laminati-ons of the heads 19 (FIG. 5) while the companion laminations have clearance cut outs or notches 31a aligned with the stripping edges and exposing the contiguous face areas of the companion laminations carrying the edges 31 and adjacent to such edges to serve as stripper stops to assist in pulling off the severed insulation.

During va stripping operation, an insulated wire W (FIG. 5) is inserted between the complementary stripping cutter edges 31 and the handle levers 10 and 11 closed on one another to eifecta crimping, creasing cutting coaction of the stripping blades 31 on the insulation of the wire, while the head laminations lexposed within the cutouts 31a at each side of the stripping orifice dened by the closed stripping cutters 31 serve as limit stops. On pulling the wire W away from the terminal portion of the wire from which the insulation is to be stripped, the terminal insulation portion is stripped while the stripped wire body pulls on through the stripper orifice.

A desirable feature of the coupling structure 12 resides in its ability to afford some resilient pressure compensation or equalization to avoid possible strain damage in the tool and to relieve excessive wear. For this purpose, the coupling structure is constructed in the form of a set of dat spring link yokes 32 ladapted to be constructed as identical stampings from suitable gauge strip or sheet metal such as spring steel. Each of the yoke members 32 has a pair of generally oppositely projecting spaced attachment ears slidably overlapping the respective outer faces of the heads 19 and secured in position by the rivets providing the pivots 13. Connecting the ears 33 are respective, preferably identical spring yokes 34 of generally U-shape, a pair of such spring yokes being attached to each pair of the ears 33 on respectively opposite sides of the ears on the longitudinal axis of the tool. By constructing the spring yokes 34 of the generally serpentine shape shown, with central portions 35 thereof inset relative to the adjacent shoulder portions spring action equivalent to a somewhat longer member is attained. That is, by this particular formation the link yoke members 32 are shorter in the longitudinal axial direction of the tool than if the spring yokes were of a uniformly arcuate form. Further, the indentation provid-ed by the inset 35 within the bifurcation provided by the handle levers 10 and 11 serves as a convenient locating, centering notch as well as stop for a wire to be cut by the severing blade portions 30. It will be observed that the relatively narrow spring yoke 34 located between the connector crimping jaws and the cut-off blades 30 affords a clearance within the link member in each instance receptive of the connector 23, and also assists in positioning the connector relative to the jaw notch 22 or 22', as the case may be.

When the handle levers 10 and 11 are pressed toward one another during any of the crimping functions of the 'tool and more particularly during connector crimping,

'the tool arms 10 and 11 may be forced'together during a crimping operation into substantially parallel relation,

resilience of the spring connector yokes can yield suficiently and the pressure applied will be substantially equal to that of the spring tension developed i'n the spring yokes.

As a distinct convenience for the user of the tool in evaluating the gauge of wire he may be working with, at least one of the hand-grip portions 18 is provided with a set of spaced holes 37 of graduated predetermined diameter corresponding to a range of different gauge `diameters as may be utilized inthe various wiring circuits i'n-an average building. By way of example gauge holes 37 for wire of eight, ten, twelve and fourteen gauge are shown on the hand grip portion 18 of the handle lever 10. Since the handle grip portion 18 is hollow as shown in FIG. 6, the gauge holes 37 afford free entry for the ends of wires being gauged.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a crimping tool, a pair olf handle levers each of which has a crimping head end portion, a couplingl structure pivotally connected to the crimping heads andconnectin-g the heads together for movement toward and away from one another by swinging of the handle levers on the connecting pivots, and opposed coactive crimping jaws on the opposed edges of said crimping heads adjacent'to said pivots and engageable with an electrical wire vferrule connector to crimp the same into firm retaining engagement with a plurality of wires encompassed by the ferrule upon squeezing said handle levers toward one another with the ferrule between the crimping jaws, said coupling structure comprisingfresilient link yokes including connecting ear portions to which the crimping heads are pivotally connected and resiliently yieldable spring portions between and connecting said ear portions whereby the yokes are yield-able on the application of excessive squeezing pressure on said handle levers during crimping to avoid damaging strains on the crimping heads.

2. `In a crimping tool, a pair of handle levers each of which has a crimping head end portion, a coupling structure pivotally connected to the crimping heads and connecting the heads together for movement toward and away from one another by swinging of the handle levers on the connecting pivots, and opposed coactive crimping jaws on the opposed edges of said crimping heads adjacent to said pivots and engageable with an electrical wire ferrule connector to crimp the same into firm retaining engagement with a plurality of wires encompassed by the ferrule upon squeezing said handle levers toward one another with the ierrule between the crimping jaws, said coupling structure comprising a pair of yoke links disposed on respectively opposite sides of the crimping heads, said yoke links comprising frame members having aligned openings therethrough affording clearance for access of a connector ferrule to said crimping jaws through said aligned openings, at least one of said frame members having a portion 1ocated adjaoent to said crimping jaws and assisting in positioning the connector relative to the jaws.

3. In a crimping tool,

a pair of handle levers each of which has a crimping head end portion,

a coupling structure pivotally connected to the crimping heads and connecting the heads together for movement toward and away from one another by swinging of the handle levers on the connecting pivots,

and opposed coactive crimping jaws on the opposed edges of said 4crimping heads adjacent to said pivots and engageable with an electrical wire ferrule cOn- 7 nector to crimp the same into firm retaining engagement with electrical wire encompassed by the ferrule upon squeezing said handle levers toward one another with the ferrule between the crimping jaws,

said coupling structure having a portion located adjacent to and aligned with said gripping jaws and ansisting in positioning the connector relative to the jaws.

4. In a crimping tool,

a pair of handle levers each of which has a crimping head end portion,

a coupling structure comprising a yoke link having -a pair of attachment portions spaced apart and each respectively overlapping one of said head end portions and a spring yoke structure between and attached to the respective attachment portions and resiliently yieldable to permit said attachment portions and said crimping head end portions to spring apart in response to excessive crimping forces,

and respective pivot members pivotally attaching vsaid attachment portions and said respective head end portions, whereby the handle levers are pivotally connected for movement toward and away from one another and relief of excessive pressure in crimping coaction of the handle levers is afforded by resilient yielding of the spring yoke structure.

5. A crimping tool as dened in claim 4, wherein said spring yoke structure is of generally serpentine shape to afford spring action equivalent to a somewhat longer member.

6. In a crimping tool of the character described, a pair lel axes and having respective crimping heads and means pivotally connecting said heads for movement toward and away from each other on actuation of the handle levers, said crimping heads having coactive complementary yof handle levers pivoted for movement about spaced paralcrimping jaws disposed inside of the pivots of said handles and comprising a crimping projection on one of said heads and a crimping jaw recess in the other of said heads receptive of said projection and operative to crimp a connector ferrule disposed in said recess, said projection having` a crimping nos-e and said recess being deined by a. pair of `crimping projections cooperatively related to said nose and said nose and said projections in the recess coacting to project into and crimp the ferrule upon movement of said handles toward one another, `said projection having in addition to said nose a pair o-f terminal crimping projections at opposite sides of said nose and extending toward said recess in the same plane as said nose and substantially shorter than said nose, and said recess being defined by wall surfaces opposing sai-d terminal projections and coacting therewith in the terminal crimping coaction of the projection and recess to crimpingly crowd 'the material of the ferrule.

References Cited by the Examiner y UNITED STATES PATENTSk 351,339 10/1886 Pullman `30.-192 751,352 2/1904 Schon 81-300 1,455,297 5/1923 Lyons et al. 81-348 2,394,807 2/1946 Robinson 7-5.2 2,411,838 ll/l946 Swengel. 2,639,754 5/1953 Macy. 2,668,464 2/1954 Paules 75.2 X 2,693,216 11/1954 Kerchner et al. Y 2,743,634 5/1956 Badeau. 2,806,229 9/1957 Pletz 81-428 X 2,920,514 1/1960 McKeehan et al 7-5,l X 3,067,489 l2/l962 Hoffman.

FOREIGN PATENTS 179,272 8/ 1954 Austria.

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. IN A CRIMPING TOOL, A PAIR OF HANDLE LEVERS EACH OF WHICH HAS A CRIMPING HEAD END PORTION, A COUPLING STRUCTURE PIVOTALLY CONNECTED TO THE CRIMPING HEADS AND CONNECTING THE HEADS TOGETHER FOR MOVEMENT TOWARD AND AWAY FROM ONE ANOTHER BY SWINGING OF THE HANDLE LEVERS ON THE CONNECTING PIVOTS, AND OPPOSED COACTIVE CRIMPING JAWS ON THE OPPOSED EDGES OF SAID CRIMPING HEADS ADJACENT TO SAID PIVOTS AND ENGAGEABLE WITH AN ELECTRICAL WIRE FERRULE CONNECTOR TO CRIMP THE SAME INTO FIRM RETAINING ENGAGEMENT WITH A PLURALITY OF WIRES ENCOMPASSED BY THE FERRULE UPON SQUEEZING SAID HANDLE LEVERS TOWARD ONE ANOTHER WITH THE FERRULE BETWEEN THE CRIMPING JAWS, SAID COUPLING STRUCTURE COMPRISING RESILIENT LINK YOKES INCLUDING CONNECTING EAR PORTIONS TO WHICH THE CRIMPING HEADS ARE PIVOTALLY CONNECTED AND RESILIENTLY YIELDABLE SPRING PORTIONS BETWEEN AND CONNECTING SAID EAR PORTIONS WHEREBY THE YOKES ARE YIELDABLE ON THE APPLICATION OF EXCESSIVE SQUEEZING PRESSURE ON SAID HANDLE LEVERS DURING CRIMPING TO AVOID DAMAGING STRAINS ON THE CRIMPING HEADS. 